Canon EOS Rebel XS

The Canon Rebel XS scored average to well in all the tests we ran. Most scores were approximately on par with the XSi, which isn’t too surprising considering the similarities of the cameras. The only areas it performed significantly worse than the XSi was in color and resolution, with the latter score reflecting the lower megapixel count of the XS. The XS outperformed the XSi in our manual noise, low light and dynamic range tests, and generally scored better than both the recently introduced Sony Alpha 200 and Olympus E-520.

Color (8.57)
Color accuracy is one of the most important features of a digital camera. When you take a picture, you want your photo to come out as close to the colors you remember as possible. You want grass to be green, grain to be amber, and mountains to be purple – or, at least as purple as they are in reality. To test how accurately the XS performs, we shoot an industry standard color chart, the Gretag Macbeth, under precisely controlled lighting conditions. The resulting images are analyzed with the application Imatest, which, in addition to other factors, tests color accuracy. The resulting image, below, shows the captured color in the outer rectangle, the luminance-corrected color in the inner square, and the ideal color in the small inset rectangle.

The ideal color in this test result represents the original color,
the outer rectangle the camera's rendition

The second chart shows the same data expressed as a vector. The ideal color is shown in a square, the captured color in a circle, and a line represents the difference. The longer the line, the greater the disparity.

The squares indicate the original color chart values,
the circles what the XS captured.

With both the XS and the XSi, the most accurate color scores were gained not by using the default shooting settings, but rather by changing the camera to Faithful Picture Style, which we used for this test. When shooting in standard mode, the colors tend to appear brighter and more bombastic, which does make for more exciting photos, but not greater accuracy. Regardless, the XS scored significantly lower than the XSi and the Olympus E-520, approximately on par with the Sony Alpha 200, and quite impressively above the Nikon D60.

Resolution (9.22)
Resolution is more than just a measure of megapixels, it’s about the level of detail that a camera can capture. A camera with a good resolution score will give you more options for cropping and zooming. We test resolution in the lab by shooting hundreds of photos of an industry standard resolution chart. These photos are taken at a number of focal distances, and analyzed through Imatest, which determines the number of alternating horizontal and vertical lines the camera can reproduce, measured in line widths per picture height, or lw/ph.

A section of the industry-standard resolution chart that we use for testing

The XS showed average performance on this test, capturing 1802 lw/ph horizontal with slight undersharpening, and 1507 lw/ph vertically with significant undersharpening. This puts it approximately at the same level as the Sony Alpha 200 and the Olympus E-520, and slightly below the Nikon D60. The Canon XSi performed significantly better in this test than the XS.

Noise
Image noise can appear in almost all digital photos, but is especially noticeable at high ISOs. It manifests itself as speckled static that is most apparent in areas of flat color, and is the bane of low light shooting.

To test the noise level of the camera, we shoot the Gretag Macbeth color chart at every available ISO, and use Imatest to measure the levels of noise across the different light sensitivities. As the Canon Rebel XS has a high ISO noise reduction feature, we shot this test with this setting both disabled and enabled to see to what extent it helps reduce noise levels.

Manual ISO (8.74)
The graph below shows how the XS performed at the each ISO. It shows the expected increase in noise as the ISO level is raised.

The Rebel XS scored well in this test. Even with noise reduction turned off, the noise levels stayed quite low. Once the high ISO noise reduction setting was enabled, the percentage of noise was shaved down even further.

The XS punched slightly above its weight in this test, beating its big brother to show a good result when manually selecting the correct ISO for the situation. It also scored a little above the Sony Alpha 200, and a bit below the Nikon D60. This means that while shooting at a high ISO in poor lighting conditions, you will get images with comparatively little noise.

Auto Noise (6.12)
Unfortunately, the XS didn’t fare quite as well in the auto noise test. For this second round of noise testing, we set the camera on auto ISO in a well-lit area, and let it choose the best ISO for the situation. The brightness of the lighting that we use is high enough that ISO 100 would produce a good image. In this situation, the Rebel XS defaulted to shooting at ISO 250. While this didn’t produce the highest score we’ve seen, it did significantly better than both the Sony and Olympus entry-level SLRs. The slightly more expensive XSi performed a little better in this test, and the Nikon D60 handily outperformed them both.

White Balance (7.03)
This series of tests measures the camera’s ability to correctly compensate for the different hues cast by different light sources. It is easy to forget is that light from the sun is different from light cast by a fluorescent bulb or from a flash, and that unless a camera can compensate for these changes, the colors of your photo will come out wrong. Most cameras have both manual and automatic white balance settings. The former is where you choose a white balance preset based on the situation you’re shooting in. The latter lets the camera set the white balance based on its own analysis.

We test white balance by shooting the standardized Gretag Macbeth color chart under a series of lighting conditions, using both manual and auto white balance settings. The resulting images are run through Imatest, which analyzes how far from known gray values the images deviate. The results shown below are exaggerated, and the color error you see while shooting will not be this great.

Auto White Balance(6.74)
For the auto white balance test, we shot with the flash, under fluorescent lights, in daylight and under a tungsten bulb, and allowed the camera to automatically set white balance for each. From these results, the XS managed to handle both the flash and the fluorescent light well, but stumbled with natural and tungsten light. This last one catches out many cameras, but is important as it’s the setting used for standard indoor incandescent lights.

Exaggerated White Balance Errors

Auto WB - Flash Illumination

Auto WB - Fluorescent Illumination

Auto WB - Daylight illumination

Auto WB - Tungsten illumination

Preset (7.31)
As with the previous test, we illuminated the Gretag Macbeth color chart with a range of light sources, but this time shot using the appropriate preset white balance. Once again, these results are exaggerated, and you will not see this level of error in your photographs.

 

Exaggerated White Balance Errors (Presets)

Flash Preset WB - Flash Illumination

Florescent Preset WB - Fluorescent Illumination

Cloudy Daylight preset WB - Daylight illumination

Tungsten preset WB - Tungsten illumination

The XS fared better using its presets over the automatic setting, which is common with most cameras. Its performance under the tungsten light was especially improved. However, it scored worse for fluorescent illumination in manual mode than it did for automatic. The reason for this is that fluorescent bulbs actually come in a number of different white levels, and the XS only has one fluorescent white balance preset, which isn’t appropriate for all situations.

Still Life
To provide a useful view of how the camera handles in everyday situations, namely shooting indoors under normal fluorescent lighting, we take a series of photos of the same two scenes at every available ISO. These photos of our loving couple and Rosie the Riveter and friends show how shooting at different ISO levels will alter color reproduction, image sharpness and noise levels. Click on the images below to see them at full size, but be aware that the files are large and may take some time to load.

Low Light (7.75)
Most photos, unfortunately, aren’t taken in ideal lighting, so a camera needs to be able to handle nighttime and indoor shooting. We test cameras in two ways to make sure they can handle these low-light situations, first taking photos at increasingly lower light levels, and second with increasingly long exposures.

The Rebel XS scored well, especially in the long exposure testing. Noise levels were low, and the color scores were accurate in both series of tests, so you can shoot both in low light conditions, and using long exposures, and expect a comparatively decent photograph at the end.

For the first test, we shoot the Gretag Macbeth chart at light levels that correspond to commonly occurring brightnesses. 60 lux is about as bright as a room lit by two small lamps, 30 lux corresponds to a room lit by a single 40 watt bulb, 15 lux equals the light provided by a computer monitor or television screen, and 5 lux equates to a single candle in a dark room. All shots were taken at ISO 1600.

The Rebel XS did well in these tests, outperforming all the cameras in our comparison group. It scored especially impressively over the long exposure trial, marking it as a camera that is great to use at night. 

The Rebel XS performed strongly in this test, with a very good dynamic range, especially at the lower ISOs. The dynamic range does decrease as the ISO increases, but this is normal. Shooting with the various types of noise reduction does nothing to alter the dynamic range, which is positive, as in some cameras these settings can lower the range of grays accurately recorded.

Canon XS Dynamic Range Scores

Physical Tour	Page 3 of 13		Components
Canon Digital Rebel XS Digital Camera Review Navigation
Intro	Physical Tour	Testing/Performance	Components
Design / Layout	Modes	Control Options	Image Parameters
Connectivity / Extras	Overall Impressions	Conclusion	Sample Photos
Specs / Ratings